The DM Lefever SBT with a solid rib was introduced in 1905, the Baker with a ventilated rib in 1909. The 1909 Remington catalog listed a matted rib or a ventilated rib ($16) on the autoloading gun. The No. 525 Stevens Repeater with a "Hollow Matted Rib" was introduced in 1911.

BUT the Prechtel SBT first appeared at the Cleveland Cartridge & Target Co. tournament in Cleveland, Ohio June 1897

The fourth annual tournament of the Cleveland Cartridge & Target Co. was held at Cleveland, O,, on June 16, 17 1897 and on the grounds of the Cleveland Gun Club.
R. E. Shelden, of Cleveland, the old-time expert, was present and shooting very well, using a single barrel, hammerless gun made by J. A. Prechtel, of Cleveland. It was one of the finest pieces of work we have ever seen in a single barrel gun. The finish was simply beautiful and the working mechanism of the gun was perfect. The gun cost about $750, is surely a pretty weapon.

Prechtel apprenticed with D.M. Lefever in Syracuse

AND some of the pre-1900 Francotte VL&D SBT imports had ventilated ribs.